Mullet is very common in the Yellow River Basin, so how to raise mullet? Let’s take a look at the mullet feeding techniques that I carefully recommend for everyone. I hope it will be helpful to you.
Rearing technology of mullet
Mullet, also known as black fish, raw fish, snakehead, talented fish, etc., belongs to the order Perciformes and the family Snakeidae. In my country, there are two genera of fish in the family Snakehead: Snakehead and Snakehead. There are 7 species in the genus Snakehead: black snakehead (and Heilongjiang subspecies), spotted snakehead, armored snakehead, eye snakehead, spotted snakehead, snakehead, and striped snakehead, as well as a white one; the moon snakehead genus only has one species, moon snakehead. Distributed in freshwater basins in tropical Africa and Asia. Except for the Yellow River Bay wetlands in Heyang and Qiachuan in the western region of Shaanxi, there are very few wetlands in other northwest regions. In recent years, snakeheaded fish have flooded in the Yinchuan Yellow River Basin. Buddhist believers in various places have introduced the use of snakeheaded fish release. Therefore, some reservoirs in Shaanxi have There are snakeheaded fish released in the wild, and snakeheaded fish are also common in the Fenghe River Basin in Xi'an. They are found in freshwater rivers, lakes, ditches, ponds, and ponds everywhere.
Ecological habits of mullet
Benthic fish usually inhabit still water or micro-flowing water with thick aquatic plants and soft bottom mud. They are found in lakes, rivers, reservoirs, In ponds and other waters. It often dives at the bottom of the water and maintains its balance by swinging its pectoral fins.
) It has strong adaptability to changes in environmental factors in the water body, especially to hypoxia, water temperature and poor water quality. When the water is deprived of oxygen, it can raise its head above the water. The back is flattened laterally. The head is long, slightly flat at the front and slightly raised at the back. Breathing oxygen in the air directly with the help of the epibranchial apparatus, which is composed of the epibranchial bones on the back of the first gill arch and the bones extending from the hyoid and mandibular bones in the gill cavity. Therefore, it can survive for a long time even in humid areas with little or no water. The survival water temperature of mullet is 0-41℃, and the optimal water temperature is 16-30℃. When the water temperature reaches above 8℃ in spring, they often move in the middle and upper layers of the water body; in the summer season, they move in the upper layers of the water body; in autumn, when the water temperature drops below 6℃, they swim slowly and often lurk in the depths of the water; in winter, when the water temperature is close to 0℃, Then they live in seclusion in the mud at the bottom of the water, unable to eat.
Has strong jumping ability. When the weather is sultry, it rains and the water rises, mullet will often jump out of the water and escape along the pond embankment; when there is impact of flowing water, the fish will also jump and escape. If there is insufficient food in the pond where it lives, it will also move to another pond. When moving, its body will be like a snake, moving forward slowly.
The growth rate is fast. According to different regions and different environments, the growth rates of black snakehead and spotted snakehead are different.
The average body length of snakehead fry hatched that year can reach 15 cm and weigh about 50 grams at the end of the year. According to specimens collected in Taihu Lake, the body length and weight of each age group are: 1 winter fish body length 14.2 ?19.2 cm, weight 115?428 grams; 2 winter fish body length 24?28 cm, weight 350?760 grams; 3 winter fish body length 32.cm, weight 605?1000 grams.
Spotted snakehead The growth rate of each age is: 1. The body length of winter fish is 19.0 to 39.8 cm, and the weight is 95 to 760 grams; 2. The body length of winter fish is 38.5 to 45.0 grams, and the weight is 625 to 1395 grams; 3. The body length of winter fish is 45.0 to 59.0 cm, and the weight is 1467 ?2031 grams.
Under artificial breeding conditions, the weight of an individual can reach 250 grams that year and 500 to 1000 grams the next year.
The feeding characteristics of mullet
It is a ferocious carnivorous fish and relatively gluttonous. Prey targets vary with fish size. Seeds with a body length of less than 3 cm feed mainly on flexipoda, cladocerans and chironomid larvae, etc. Seeds with a body length of less than 3 to 8 cm feed on aquatic insect larvae, tadpoles, shrimps, larvae, etc. Adult fish over 20 centimeters prey on various small fish and frogs (small fish mainly refer to crucian carp, meal sticks, red-eyed trout, loach and various juvenile fish). Snakehead fish swim slowly [1], but prey They generally do not chase prey, but hide near aquatic plants or other shelters, and pay close attention to the surrounding movements. Once they find fish or other palatable live bait swimming nearby, they will quickly attack and catch them in one fell swoop. Snakehead fish have a large food intake and can often swallow about half of their body length of live bait, and the maximum capacity of their stomach can reach about 60% of their body weight. According to an autopsy, a 500-gram snakehead swallowed eight 10-centimeter-long grass carps in a relatively short period of time. Snakehead fish also have the habit of cannibalism and can devour individuals of the same species that are less than two-thirds of their body length.
The size of its food intake is closely related to the water temperature. In summer, when the water temperature is high, they are quite gluttonous and eat a lot of food; when the water temperature is lower than 12°C, they stop eating. Under artificial breeding conditions, when animal feed is insufficient, they can also feed on artificial compound feeds such as bean cakes, vegetable cakes, and fish meal.
Like the anchovy, it feeds on fish, shrimp, etc. But its hunting method is different from that of the anchovy, and it never actively chases its prey. Snakehead often lurk in shallow water areas with turbid water and overgrown aquatic plants. If the water is clear and the water flow is slow or calm, they will often hide under the aquatic plants or in the still water layer. When catching food, it never relies on its strong body's ability to swim quickly to chase small fish, but instead uses cunning means to achieve the purpose of chasing food. When it finds a small fish, it hides in the nearby aquatic plants and peeps quietly, waiting for the other party to relax its vigilance and swim near it. Then it suddenly rushes forward, bites the small fish in one fell swoop and devours it in a sudden attack.
Reproductive habits of mullet
The spawning season varies depending on the climatic conditions in different places. In southern China, the season is from mid-April to mid-September, with peaks in May and June; in central China, the season is from May to July, with June being the most concentrated. The breeding water temperature is 18℃~30℃, and the optimal water temperature is 20℃~25℃.
The age of sexual maturity also varies slightly in different regions. In South China, fish usually have mature gonads in 1 winter with a body length of more than 20 centimeters, while in the Yangtze River Basin, it takes 2 winters and a body length of about 30 centimeters to lay eggs. Snakehead can reproduce naturally in ponds, rivers, reservoirs and other waters. Spawning grounds are generally located in shallow water areas with lush aquatic plants. The number of eggs carried and the number of eggs laid are related to the size of the brood. The number of eggs conceived by snakehead is usually about 23,000 eggs per kilogram of body weight, and the number of eggs laid by 0.5 kg spotted snakehead is generally 08,000 to 1,000 eggs, and some individuals can reach 11,000 to 12,000 eggs. The method of laying eggs is to create a nest type. Before spawning, sexually mature male and female broodstock swim in pairs at the spawning site. The females use their mouths to collect aquatic plants, plant fragments and foam to build a slightly circular structure with a diameter of about 0.5 to 1 meter, floating on the water surface. After the nest is built, on a calm morning before sunrise, the female and male fish chase each other and are in estrus. Then the female fish lies under the nest close to the water surface, with her abdomen upwards in a supine state, and her body slowly shakes to give birth. The eggs are laid on the nest. At the same time, the male fish ejaculates here in the same posture. The fish spawns in multiple stages. After spawning, the broodstock fish stay at the bottom of the nest to protect the eggs from harm.
The eggs are golden yellow, have oil balls, and are floating eggs with a diameter of about 2 mm. The egg diameter of snakehead Heilongjiang subspecies is slightly smaller, about 1.5 mm. The incubation time of sperm eggs is related to the water temperature: when the water temperature is lower, the incubation time is longer; when the water temperature is higher, the incubation time is shorter. The total length of newly hatched fry is 3.8 to 4.3 mm. The body is covered with melanocytes. The pectoral fin primordium appears. The oil globule and yolk sac make the body significantly enlarged. It looks like a tadpole. It often lies on its side and floats near the water surface. It has poor movement ability and relies on Born by absorbing egg yolk. When the seedling is 6.1 to 6.2 mm long, the pectoral fins, gill slits and mouth have all appeared. The position of the oil ball in the yolk has moved to the abdomen. It often lies supine on the water surface and can make short-range vertical movements downwards. They start feeding, and the parent fish join the group for protection. When the total length is 7.4 to 7.5 mm, the whole body is black, the yolk sac disappears, they swim in groups, and the parent fish start feeding, and the parent fish join the group for protection. When the total length is 15.5 mm, the body is yellow, the ends of the odd fins are black, the dorsal fin, pectoral fin and anal fin have fins, and the pelvic fins begin to show fins, and they start to swim dispersedly, and the parent fish also stops guarding the young.
Protecting young fish
The parent fish has the habit of protecting young fish. Whenever the breeding season comes, the male and female broodstock will choose the spawning location in swamps, lakes, bottoms, banks among aquatic plants in rivers, or shallow water beaches with reeds.
Before spawning, male and female broodstock fish jointly pick up aquatic plants or plant fragments to build fish nests. The size of the nest depends on its individual size. The nest is slightly ring-shaped and the eggs are laid in the nest.
After spawning, a pair of parent fish or only the male fish lurk in the fish nest, or guard the eggs near the nest to prevent other fish or frogs from getting close to avoid harm.
For newly hatched larvae, the front part of the body is significantly enlarged by the yolk sac, and the larvae lie on their sides and float gently on the water surface, with the parent fish guarding the bottom of the larvae. As the larvae develop, the yolk sac disappears and the young fish can swim vertically, but only near the fish nest. The defensive activities of the parent fish are more intense. If other fish or frogs try to attack the seedlings, the parent fish will go all out to drive them away.
When the seedlings grow to 10-30 mm, their mobility becomes stronger, their movements are lively, and their range of activities also expands. At this time, the parent fish and the young fish gather together and shuttle around the fry to strengthen protection. When the seedlings reach 40-50 mm, the body color of the fish changes from yellow-green to dark green, fins appear on each fin, and it has strong swimming ability. At this time, the young fish begin to disperse and live independently, and the male and female parent fish will end at this time. It spends its annual life as a nurse, leaving the fish nest and looking for its own habitat.
Mullet stocking technology
Selection of broodstock pond: The size of the stocking pond should be determined according to the amount of each reproduction. For example, if you can breed 50 to 70 pairs at a time, and basically follow the principle of stocking one pair per 10 square meters, choose a pond of 0.6 to 1 acres; if you can only breed 30 to 40 pairs at a time, choose a pond of 0.3 to 0.6 acres. The main reason is that when the gonads of the broodstock are mature, it is best to catch them once to induce labor, and it is not advisable to catch them multiple times. This is because the catching rate of snake net fishing is low. Generally, the pond water is drained and captured, which is very irritating to the parent fish. If the pond is too large, the broodstock will be overly concentrated, drained for many times, and caught for many times, which will not only waste manpower and material resources, but also cause strong stimulation of the broodstock many times, which will cause the gonads of the broodstock to degenerate and affect the inducing effect of subsequent batches. Therefore, the size of the broodstock pond should be selected based on the stocking amount of each pond and the breeding amount of each time. The appropriate depth of the pool is 1.5 to 2.0 meters, the irrigation water is 1.0 to 1.5 meters, and the pool ridge is more than 0.5 meters above the water surface. If the depth of the pond is only 1.0 to 1.2 meters, the water can still be filled to 0.8 to 1.0 meters. A bamboo fence or an old fishnet fence with a height of 1.5 meters should be inserted around it to prevent snakeheads from jumping out of the pond.
Preparation for stocking: Clean and disinfect the fish pond before stocking. Generally, dry pond disinfection is used. If the silt is too thick, dig out the excess silt, leaving about 20 centimeters. Use 50 to 75 kilograms of quicklime per mu to clear the pond. After 10 days of irrigation, broodstock can be stocked. A small amount of water peanuts, water hyacinth and other aquatic plants are cultivated in the pond to provide shelter and habitat for snakeheads and to prevent escape. If the selected broodstock is wild, some small miscellaneous fish can be stocked in the broodstock pond. The size should be small and should not be too large.
Key points for stocking broodstock: The key to stocking broodstock is density, time and male-to-male ratio. The stocking density is generally 100 to 150 kilograms per mu, with a maximum of no more than 200 kilograms. It should be determined according to the size of the broodstock, usually around 150 to 250 fish. The density should not be too high or too low. If it is too high, it will affect the activity space of the broodstock. If it is too low, it will be difficult to domesticate the broodstock, especially the wild broodstock. These will affect the gonad development of the broodstock. The time is scheduled for September. In September, the water temperature is between 25 and 30°C, and gradually turns cooler from high temperature, which is conducive to the cultivation of broodstock before overwintering, and the feeding is relatively strong. Broodstock are caught and transported, especially wild broodstock, when they arrive in a new ecological environment and often do not look for food. However, stocking in September can still allow them to adapt to the new environment through more than 2 months of domestication, actively ingest food, restore physical fitness, promote the development of gonads, and increase the number of eggs pregnant by female fish. When stocking, males and females are basically mixed in a ratio of 1:1. At this time, it is difficult to distinguish between male and female, so we can only say that the stocking number is basically slightly larger than the actual requirement. Before entering the pond, disinfect the broodstock with 2% to 3% salt water or take a medicated bath with 30 mg/kg formalin solution for about 10 minutes. After disinfection, put it into the prepared broodstock pond.
Specialized cultivation technology of mullet
1. The fish pond should be chosen to be ventilated and sunny, with sufficient water source, an area of ??1 to 5 acres, a water depth of 1 to 1.5 meters, and some water planting around it. Floating lotus or water peanuts, and fenced with netting in lower areas, can not only prevent the mullet from escaping, but also provide concealment and shade, creating a good ecological environment and conducive to the growth of mullet.
2. After selecting the fish pond for clearing and disinfecting, drain the pond water first, use 140 to 150 kilograms of quicklime per 667 square meters to dissolve the water, sprinkle the entire pond evenly, and use rakes and other tools to turn over the mud to fully disinfect. One week before stocking mullet species, fill the pond water to a depth of 1 meter and apply appropriate base fertilizer to improve the water quality.
3. There are generally two sources of fish for stocking, one is wild and the other is artificially bred. However, no matter which fish species come from, they must be screened before being put into the pond. Fish species with basically the same specifications should be bathed in 3% to 5% salt water for 5 to 10 minutes, and then put into the same fish pond.
The stocking density depends on the water source, injection and drainage conditions, source of bait fish, etc. Generally speaking, 6,000 to 10,000 fish species with a length of 3 cm to 5 cm are stocked in 667 square meters; fish species with a length of 10 cm to 15 cm are stocked , 4,000 to 6,000 fish are stocked; about 2,000 fish species about 20 cm are stocked. If the water source, injection and drainage conditions are good, and the source of bait fish is sufficient, the stocking density can be appropriately increased.
4. Feed artificial intensively cultured snakeheaded fish with bait, mainly using low-value fresh small fish and shrimp as the main bait. Because wild or some artificially bred fish species eat live bait, the fish species should be stopped for a day or two after being placed in the pond, and then an appropriate amount of dead bait should be fed around the pond every morning to acclimate them, and then gradually moved to one part of the pond. Feed. After the fish gets used to eating dead bait, feed it once a day at 9 a.m. and 4 p.m. The daily feeding amount is 5% to 10% of the fish's body weight, and it can be flexibly controlled according to weather, water temperature, growth, feeding and other conditions.
5. Daily management: Snakeheaded fish are not prone to disease in natural water bodies or under rare conditions. However, under artificial intensive conditions, if prevention and treatment is not appropriate, fish diseases will break out, causing serious economic losses. . Judging from the author's practice over the past few years, common diseases of mullet include saprolegnia, rotten skin, ascites, gill rot, etc. If prevention and control measures are taken properly, fish will rarely or never get sick. Therefore, during the breeding process of mullet, one should frequently check the water quality, fish condition, salvage residual bait, prevent escape, etc., and deal with any abnormality in time if any abnormality is found.